The present invention relates to an electrostatic image developing toner and a production method of the same.
In order to achieve high quality images similar to conventional photographic images when employing digital copiers and laser printers, preferred are images with high glossiness, which are prepared by employing smaller diameter toner particles. In order to decrease the toner particle diameter, toner particle preparation, employing a polymerization method, has received attention.
As described in Japanese Patent Publication Open to Public Inspection No. 2001-201887, known a pulverization type toner comprises at least a binding resin, a colorant and wax. Said patent publication discloses an electrostatic image developing toner in which, in regard to the GCP determined molecular weight of toner components which are soluble THF, the ratio of the molecular weight of at least 5xc3x97105 in an integral molecular weight distribution is at most 1 percent by weight; the ratio of the molecular weight of at most 3xc3x97103 in the integral molecular weight distribution is at most 30 percent by weight; and the ratio {W(5xc3x97103)/W(1xc3x97105)}, of the ratio {W(1xc3x97103)} of at most 1xc3x97105 in the molecular weight distribution to the ratio {W(1xc3x97105)} of at least 105 in the integral molecular weight distribution, is from 15 to 50. Further, said patent publication discloses that by employing said toner, exhibited are effects such as improvements of fixability at lower temperatures as well as offsetting resistance, and formation of images with higher glossiness.
However, when the aforesaid techniques are applied to toner prepared by a polymerization method, the resultant image glossiness, fixability at lower temperatures, and fixing ratio do not meet market demands.
In the case of toner particles prepared by the known polymerization method and especially in the case of colored toner particles, resins, which have a lower molecular weight and a narrower molecular weight distribution, are suitable. On the other hand, when taking into account the aspect of image durability, resins comprised of higher molecular weight components are preferred. As a result, problems have occurred with compatibility between glossiness and image durability.
For example, in Japanese Patent Publication Open to Public Inspection No. 9-190012, the insoluble amount of crosslinked polymerization toner is specified, while in Japanese Patent Publication Open to Public Inspection No. 10-133419, mechanical strength is enhanced by specifying the kind of crosslinking agents. By so doing, enhancement in image durability is achieved, while characteristics of the resultant glossiness do not reach a satisfactory level. As a result, said compatibility between image durability and glossiness characteristics is not sufficiently achieved.
Further, Japanese Patent Publication Open to Public Inspection No. 2001-083730 discloses a method in which dispersion of aggregated particles comprised of fine resinous particles, as well as colorant particles, is prepared by mixing a dispersion in which fine resinous particles, having a diameter of at most 1 xcexcm, and colorant particle dispersion, and subsequently, an electrostatic image developing toner is prepared via a process which fuses and coalesces said aggregated particles. Said patent publication also describes that by adjusting a crosslinked molecular weight, Mc, to the range of 3.5xc3x97106 to 7.5xc3x97108 and by holding the relationship of 14.0xe2x89xa6 Log10(Mc/Me)xe2x89xa616.5 between crosslinked molecular weight, Mc, and crosslinking density, Me, it becomes possible to simultaneously improve fixing characteristics such as adhesion properties of fixed images onto a fixing sheet, peeling properties of fixed sheets, hot offsetting resistance, surface glossiness of fixed images, and transparency of OHP, and further to enhance charging uniformity and satiability, while decreasing background staining as well as toner scattering.
However, even though this technique is employed, folding resistance of fixed images does not fully meet market needs, and further improvement has been demanded.
An object of the present invention is to provide an electrostatic image developing toner which results in excellent image glossiness, low temperature fixability, and fixing ratio, as well as exhibiting excellent folding resistance, and a production method of the same.
1. An electrostatic image developing toner comprising a resin and a colorant, wherein said resin comprises a polymerization component of a polymerizable monomer having a polar group in an amount of 1.0 to 10.0 percent by weight, as well as a polymerization component of a polyfunctional polymerizable monomer in an amount of 0.1 to 10.0 percent by weight; ratio (A/B), wherein A is the area of a chromatograph curve in the molecular weight region of 60,000 to 1,000,000, based on GCP measurement of a THF soluble component of toner and B is the entire area of said chromatograph curve, is from 0.5 to 20.0 percent; and either a peak or a shoulder is positioned in the molecular weight region of 5,000 to 20,000.
2. An electrostatic image developing toner wherein the polyfunctional polymerizable monomers are the compounds represented by Formulas (1) through (4). 
In the formula each of R1 and R2 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, n1 is an integer of 1 to 32. 
In the formula each of R3 and R4 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, each of m1 and m2 is an integer, the sum of m1 and n2 being 1 to 32. 
In the formula each of R5 and R6 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, n3 is an integer of 1 to 32. 
In the formula each of R7 and R8 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, each of m4 and n4 is an integer, the sum of m4 and n4 being 1 to 32.
3. An electrostatic image developing toner wherein the toner is prepared via a process in which resins are prepared by polymerizing polymerizable monomers in a water based medium.
4. An electrostatic image developing toner wherein toner is comprised of toner which is prepared via a process in which resinous particles are aggregate-fused in a water based
5. A production method of an electrostatic image developing toner described in any one of 1. through 4. above, comprising a process in which a binding resin is prepared via a process of polymerizing a polymerizable monomer in a water based medium.
6. A production method of an electrostatic image developing toner described in any one of 1. through 4. above, comprising a process in which the toner particles are prepared via a process of coagulating and fusing binder resin particles in a water based medium.
7. A production method of an electrostatic image developing toner described in any one of 1. through 4. above, comprising a process in which the toner particles are prepared via a process of salting-out, coagulating and fusing binder resin particles prepared by polymerizing a polymerizable monomer and colorant particles in a water based medium.
8. A production method of an electrostatic image developing toner described in any one of 1. through 4. above, comprising a process in which the toner particles are prepared via a process of salting-out, coagulating and fusing binder resin particles prepared by multi-step polymerizing a polymerizable monomer and colorant particles in a water based medium.
9. A production method of an electrostatic image developing toner described in any one of 1. through 4. above, comprising a process in which the toner particles are prepared by forming a binder resin layer by salting-out, coagulating and fusing binder resin particles on a colored particles comprising resin particles and colorant particles.
10. An electrostatic image developing toner prepared by one of production methods described in any one of 5. through 9. above.
11. An image forming method comprising visualizing electrostatic latent image formed on a photoreceptor, and transferring and thermally fixing the visualized image to a recording media, wherein the electrostatic latent image formation is conducted by digital exposure on the photoreceptor, the thermally fixing is conducted by a fixing unit comprising endless belt shaped film, and the visualizing is conducted by a toner described in any one of 1. through 4. and 10. above.